Featured post

How to Decode TLV Quickly

In TLV, the format is Tag, Length, and Value. The TLV protocol needs this type of data. Here you will know how to decode TLV data. According to IBM , TLV data is three parts. The tag tells what type of data it is. The length field denotes the length of the value. The Value-field denotes the actual value. Structure of TLV. TLV comprises three field values.  Tag Length Value EMV formulated different tags. They have their meanings. Usually, the Tag and Length together takes 1 to 4 bytes. The Best example for TLV. In the below example, you can find the sample TAG, LENGTH, and VALUE fields. [Tag][Value Length][Value] (ex. " 9F4005F000F0A001 ") where Tag Name =  9F40 Value Length (in bytes) =  05  Value (Hex representation of bytes. Example, "F0" – 1-byte) =  F000F0A001 In the above message, tag 9F40 has some meaning designed by EMV company. Here  you can find a list of EMV Tags. How to read the TLV Tag: 1 or 2 bytes Length: Length of the Value. F0-00-F0-A0-01 ==> 5 By
Post a Comment

6 Advantages of Columnar Databases over Traditional RDBMS

In traditional RDBMS, when a data source is accessed by multi users at single time, then database will go into deadlock state.

One of the advantages of a columnar model is that if two or more users want to use a different subset of columns, they do not have to lock out each other.

(Superior benefits for NoSQL Jobs)
        (Superior benefits for NoSQL Jobs)
This design is made easier because of a disk storage method known as RAID (redundant array of independent disks, originally redundant array of inexpensive disks), which combines multiple disk drives into a logical unit. Data is stored in several patterns called levels that have different amounts of redundancy. The idea of the redundancy is that when one drive fails, the other drives can take over. When a replacement disk drive in put in the array, the data is replicated from the other disks in the array and the system is restored.

The following are the various levels of RAID:

RAID 0 (block-level striping without parity or mirroring) has no (or zero) redundancy. It provides improved performance and additional storage but no fault tolerance. It is a starting point for discussion.

In RAID 1 (mirroring without parity or striping) data is written identically to two drives, thereby producing a mirrored set; the read request is serviced by either of the two drives containing the requested data, whichever one involves the least seek time plus rotational latency.

In RAID 10 (mirroring and striping) data is written in stripes across primary disks that have been mirrored to the secondary disks.

In RAID 2 (bit-level striping with dedicated Hamming-code parity) all disk spindle rotation is synchronized, and data is striped such that each sequential bit is on a different drive. Hamming-code parity is calculated across corresponding bits and stored on at least one parity drive. This theoretical RAID level is not used in practice.

In RAID 3 (byte-level striping with dedicated parity) all disk spindle rotation is synchronized, and data is striped so each sequential byte is on a different drive.

RAID 4 (block-level striping with dedicated parity) is equivalent to RAID 5 except that all parity data is stored on a single drive. In this arrangement, files may be distributed between multiple drives.

RAID 5, RAID 6, and other patterns exist; many of them are marketing terms more than technology. The goal is to provide fault tolerance of drive failures, up to n disk drive failures or removals from the array. This makes larger RAID arrays practical, especially for high-availability systems. While this is nice for database people, we get more benefit from parallelism for queries.

Comments

Post a Comment

Thanks for your message. We will get back you.

Popular posts from this blog

How to Fix Python Syntax Errors Quickly

Image
In Python, you can call parsing errors Syntax errors. How to fix the syntax errors quickly, I can show in this post. Also, check Python Syntax Errors Cheat Sheet. What is Python Syntax Error? If you run the Python code, the interpreter first parses the logic. If any errors found, it is the developer's responsibility to fix them. Courtesy: Python documentation. >>> while True print ( 'Hello world' ) File "<stdin>" , line 1 while True print ( 'Hello world' ) ^ SyntaxError : invalid syntax How to Fix the Syntax Error? First, check for the line number. In the above case, it is '1'. Then look for the symbol '^'. The issue is at the PRINT function. The reason is before the PRINT function you need a colon ':'. That is the reason, you are getting error. This is a syntax error. Find below the corrected logic: >>> while True : print ( 'Hello world' ) File "<stdin
Read more

Hyperledger Fabric: 20 Real Interview Questions

Image
I am practicing Hyperledger. This is one of the top listed blockchains. This architecture follows R3 Corda specifications. Sharing the interview questions with you that I have prepared for my interview. Though Ethereum leads in the real-time applications. The latest Hyperledger version is now ready for production applications. It has now become stable for production applications. The Hyperledger now backed by IBM. But, it is still an open source. These interview questions help you to read quickly. The below set of interview questions help you like a tutorial on Hyperledger fabric. Hyperledger Fabric Interview Questions 1). What are Nodes? In Hyperledger the communication entities are called Nodes. 2). What are the three different types of Nodes? - Client Node - Peer Node - Order Node The Client node initiates transactions. The peer node commits the transaction. The order node guarantees the delivery. 3). What is Channel? A channel in Hyperledger is the subnet of
Read more

7 AWS Interview Questions asked in Infosys, TCS

Image
I have shared 7 amazing AWS interview questions for your quick reference. 1). What is AWS? Amazon Web Services (AWS) provides on-demand computing resources and services in the cloud, with pay-as-you-go pricing. For example, you can run a server on AWS that you can log on to, configure, secure, and run just as you would a server that's sitting in front of you 2). What you can do with AWS? Store public or private data.  Host a static website. These websites use client-side technologies (such as HTML, CSS, and JavaScript) to display content that doesn't change frequently. A static website doesn't require server-side technologies (such as PHP and ASP.NET).  Host a dynamic website or web app. These websites include classic three-tier applications, with web, application, and database tiers. Support students or online training programs. Process business and scientific data. Handle peak loads.  3). What is the Security group? A security group acts as a virtual firewall for
Read more